diff --git a/etc/apt/preferences.d/firefox b/etc/apt/preferences.d/firefox
new file mode 100644
index 00000000..e5ecaa3c
--- /dev/null
+++ b/etc/apt/preferences.d/firefox
@@ -0,0 +1,4 @@
+# On Debian Testing, Firefox is better supported in Sid
+Package: firefox firefox-esr
+Pin: release n=sid
+Pin-Priority: 990